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gh-85747: Active voice & suggested edits, 'running/stopping loop' & 'callbacks' subsections of asyncio-eventloop.rst #100270

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Merged
merged 10 commits into from
Feb 7, 2023
42 changes: 24 additions & 18 deletions Doc/library/asyncio-eventloop.rst
Original file line number Diff line number Diff line change
Expand Up @@ -186,19 +186,24 @@ Running and stopping the loop
.. coroutinemethod:: loop.shutdown_default_executor(timeout=None)

Schedule the closure of the default executor and wait for it to join all of
the threads in the :class:`ThreadPoolExecutor`. After calling this method, a
:exc:`RuntimeError` will be raised if :meth:`loop.run_in_executor` is called
while using the default executor.
the threads in the :class:`~concurrent.futures.ThreadPoolExecutor`.
Once this method has been called,
using the default executor with :meth:`loop.run_in_executor`
will raise a :exc:`RuntimeError`.

The *timeout* parameter specifies the amount of time the executor will
be given to finish joining. The default value is ``None``, which means the
executor will be given an unlimited amount of time.
The *timeout* parameter specifies the amount of time
(in :class:`float` seconds) the executor will be given to finish joining.
With the default, ``None``,
the executor is allowed an unlimited amount of time.

If the timeout duration is reached, a warning is emitted and executor is
terminated without waiting for its threads to finish joining.
If the *timeout* is reached, a :exc:`RuntimeWarning` is emitted
and the default executor is terminated
without waiting for its threads to finish joining.

Note that there is no need to call this function when
:func:`asyncio.run` is used.
.. note::

Do not call this method when using :func:`asyncio.run`,
as the latter handles default executor shutdown automatically.

.. versionadded:: 3.9

Expand All @@ -213,22 +218,23 @@ Scheduling callbacks
Schedule the *callback* :term:`callback` to be called with
*args* arguments at the next iteration of the event loop.

Return an instance of :class:`asyncio.Handle`,
which can be used later to cancel the callback.

Callbacks are called in the order in which they are registered.
Each callback will be called exactly once.

An optional keyword-only *context* argument allows specifying a
The optional keyword-only *context* argument specifies a
custom :class:`contextvars.Context` for the *callback* to run in.
The current context is used when no *context* is provided.

An instance of :class:`asyncio.Handle` is returned, which can be
used later to cancel the callback.
Callbacks use the current context when no *context* is provided.

This method is not thread-safe.
Unlike :meth:`call_soon_threadsafe`, this method is not thread-safe.

.. method:: loop.call_soon_threadsafe(callback, *args, context=None)

A thread-safe variant of :meth:`call_soon`. Must be used to
schedule callbacks *from another thread*.
A thread-safe variant of :meth:`call_soon`. When scheduling callbacks from
another thread, this function *must* be used, since :meth:`call_soon` is not
thread-safe.

Raises :exc:`RuntimeError` if called on a loop that's been closed.
This can happen on a secondary thread when the main application is
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